This is a recent project I am still working on.
First of all I start off by making thumbnails of compositions. When I am happy I make the full scale drawing and finalize it by inking it in. This is so that I will always have something to go back to with out having it fade away. I've had bad experiences with smudged drawings...
I usually use tracing paper to transfer the drawing on to the good stock. There are other ways such as using a light box.
Next I lay down the mid colors. Then I go darkter and light for last.
I finish the illustration and scan it into the computer and adjust the colors if needed.
And voila, we've got an illustration.